Long Crank 2010 E550....
 

Would like to know if anyone out there is experiencing this issue. I have about 49k miles and during the last 10-15k, I've had this intermittent long crank problem. With key or keyless-go, the car will crank for 6-7 seconds before starting. There have been two occasions when the car didn't start, but it always started on the second try. It usually happens after the car is warm. I have taken the car to my dealer and local indie but, no one can ever reproduce. No codes either. I have already replaced plugs, crankshaft position sensor, battery (under warranty) and had fuel injectors professionally cleaned. Kinda getting tired of throwing $$$ at it. Any ideas would be greatly appreciated.....

I've had it happen twice. I have 46,000. Probably some electrical quirk. As you said, the car eventually starts, so until something fails I won't do anything.
The CPS will throw a code if it is bad and not working intermittently. Why did you replace it?

You're absolutely right, the CPS should throw a code. The CPS was an issue for MB V8s previously. Our engine was a carry over in '10. I found an almost identical issue on the w211 forum. The part is pretty inexpensive and I purchased OEM online and had my indie install (?1/2 labor). Hard to deny, I basically threw that money away because it didn't make a difference at all.

I replaced my CPS in my '04 E500 when it failed. Like you said they were prone to failure and the indicator was a long crank every so often telling you it was about to go. It was a cheap and easy fix also. This issue is sporadic enough that I just chalk it up to typical MB gremlins. Once again, it could be electrical or maybe a fuel pressure issue that sorts itself after the first long crank. My battery gets weak sometimes if I don't drive longer distances and weak batteries cause all kinds of issues with modern cars. I see it all the time on my other cars as well. Just keep your 1-800-MB number handy when the problem identifies itself and your car won't start at all. Then come back here and share with us what the problem ended up to be. :y

Think I'm gonna take your advice and keep that 800 number readily available. My E is doing the long crank 3-4 times per week. You'll know what happened when I come back and post a review of my new C class loaner.

You make a good point about those batteries. I picked up a CTEK MF3300 battery tender a few months ago off amazon. That was probably the most worthwhile purchase I've made so far.

Yep, I use the CTEK as well. I find them to be the best trickle chargers on the market. I have literally brought an almost dead battery back to full power over a few days on those chargers. Pretty amazing.
3-4 times a week is a lot, for this long crank so something must be up. definitely come back if your car fails on you and let us know. A lot of people rely on these forums to help troubleshoot their issues. I just hope it goes in your driveway and not while you are away from home.

Even when you've left the car for a few nights at the stealership they still can't reproduce the issue?

Am seeing same problem
 

Thank you for posting on this; I'm experiencing the same problem.

My car is a 2010 E550, 74k miles.

Aside from one or two exceptions the problem has only occured when the engine is hot and has stood for a few minutes, like going into a store. I'd say the problem occurs every tenth or so start when warm.

I'm having a hard time making sense of the symptoms. It seems (can't claim to be 100% objective) that the starter will bog down a little and then spin at a good speed and the engine with take maybe three seconds to start. If it doesn't bog down it will start normally. It always starts on the first press of the button; it just sometimes takes abnormally long.

I thought it may have been a bad starter ground (resistance increasing when hot) so checked the starter wiring, cleaned all connections but no difference. It may also be the starter.

I also thought maybe it was a fuel pressure issue, but I've not put together the parts to measure the rail pressure. But I did try waiting a few seconds with the ignition on (to run the fuel pump) before cranking. I don't think it made any difference, for sure it didn't eliminate the problem.

I did change the CPS, didn't make any difference.

Lastly I did change the battery last year (old one died), I think it was towards the end of summer, for a while I thought that had fixed the issue. However a few months ago the problem returned.

Peter

Peter, You absolutely nailed the problems I'm having. For a long time, I experienced the starter bogging and the long crank. The former improved after I got the new battery and the CTEK. Now I'm left with the long crank. I have left the car overnight with the MB dealer and the indie. The problem can NEVER be reproduced. When I had the fuel system service a few weeks ago, I asked my indie to check the fuel pumps. They were thinking there might be an issue with the fuel pressure regulator.... However, the rail pressure was normal. Back to the drawing board.

Chances of this helping are probably nil. I had a similar problem on a different car. The service guy told me to quit touching the gas pedal when the car was off. I thought he was crazy, but sure enough I would occasionally touch it getting in the car. I had no idea I was doing it until I paid attention. The tech said it confuses the computer and in my case caused the long crank. Or maybe your gas pedal is loose or something?

My 550 has always had a bog on the cold startup. Turn key, wait a moment while fuel pump primes, then turn to start, initial bog and then typical whirring starter and fire-up. I thought the bog was just a normal part of the sequence. Maybe not normal? ( I have keyless go, but don't like the start button)
4shizzle- Sounds like you have definitely checked all of the usual suspects in this.
ttoE550- That is an interesting theory. I set the damn parking brake all the time with my fumble feet; not sure if I touch the gas.

ive had this problem with my 10 550 , took a car to dealership for other issue , and when I came back to pick it up they said they have replaced starter too , no problems after that (and I thought before the battery was the issue , I was wrong , its the starter)

Thanks for sharing that info belarus. You made my day! Now the fun starts....my CPO warranty ended last month. You'd think a bad starter would throw a code!

it probably would throw a code , but because it happens once in a while and not all the time , it doesnt , my opinion..
I remember you push the button and then hear that sound of trying to start engine for like 4-6 seconds.. n then it finallt goes lol
atleast you now know the problem... 😄

http://pages.ebay.com/motors/link/?nav=item.view&id=291241644053&alt=web

and maybe an hour or 2 of labor at a indy shop

Thanks Belarus, that part will help many of the good folks on this thread. Unfortunately, my car isn't a 4matic. But, you definitely gave me new hope in getting this squared away once and for all. I've ordered parts from that ebay seller before, gonna search their site and see what I come up with.

Mine isnt 4 matic either :)

no problem at all , feel free to ask questions:zoom:

Quick update. Starter gets here tomorrow. Plan to have it installed next wednesday. I'll let everyone know how things go afterwards. Stay tuned.

Good deal. I'm personally having a difficult time understanding how these symptoms can be caused by a bad starter. Please let us know if it continues or stops after you have the new one in there for a few weeks.

So I had my starter installed today. Happy to report that things seem pretty promising so far. Mechanic even said it started a lot "stronger". No bog or long cranks, but it has only been in a few hours. I'll post some updates over the next few weeks.

Nice work and thanks for the follow up

werd. Please come back and let us know if that solved your problem for good.

bad starters won't throw a code as its not related to the emissions system. It could, however, potentially throw a code that can be found through SDS.

yea let us know if that fixed your problem or not

I also experienced intermittent long cranks on my coupe for well over a year. I took it to the dealer several times and the battery was replaced twice because it tested bad and they could not replicated the startup problem. Last Saturday the car stated making a grinding noise and would not turn over so i had it towed to dealer and turns out the starter was bad. The tech also noted that the starter going bad was the cause of my premature battery failure.